Material sample transfer system



Sept. 23, 1969 R. E. J. PUTMAN MATERIAL SAMPLE TRANSFER SYSTEM mm NQ mmzmxgrk Oh EMFDQZOO Filed Dec.

mmJJOmPzOu mvENToR' Richard E. J. Putmon W ITNESSES:

wy/2M ATTORNEY 3,468,166 MATERIAL SAMPLE TRANSFER SYSTEM Richard E. J. Pullman, Penn Hills, Pa, assignor to Westinghouse Electric Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Filed Dec. 26, 1967, Ser. No. 693,568 Int. Cl. G01n 1/10 U.S. Cl. 73-421 4 Claims ABSTRACT OF THE DISCLOSURE In the operation of many material treatment plants, such as a minerals benefication plant including a mill group producing a slurry from ore supplied to the mill group, it is desirable to remove a sample of the output product for analysis, for example in regard to particle size classification and desired X-ray studies. The present invention provides a fluid slurry sample transfer system operated by a computer such that a controlled product sample providing a transfer system for removing a product sample from the output production of the treatment plant is effective and then the system is operative to transfer that product sample as a separate entity to a remotely located analysis apparatus to enable the latter analysis apparatus to be centrally positioned and commonly shared by a plurality of such material sampling units and perhaps even a plurality of similar treatment plants.

The cross reference to related applications The present invention is related to the invention disclosed in the copending patent application entitled Slurry Particle Size Determination by the same inventor and filed Dec. 14, 1966, Ser. No. 601,608 and assigned to the same assignee.

Background of the invention In large mineral benefication plants where the lines of equipment are often many hundreds of yards in length it is often considered prohibitive in cost to even attempt to improve the operation of the plants by means of instrumentation. As an example of such a plant, a copper concentration mill may be considered with the mill having in the order of 13 groups of ball mill equipment, with each such group being approximately 30 yards away from any other group in the mill. Each mill group is producing a slurry from infeed ore to provide the feed stock for a subsequent flotation stage of the benefication process. It is desired in the operation of such a benefication plant to provide a centrally located common product sample analysis system to permit both particle size determination and X-ray analysis of the product sample which sample can be taken from any selected one of the plurality of mill groups. In this manner the expensive equipment is concentrated in one location and may be considered as a central on-stream analytical laboratory. By limiting the expensive and vulnerable equipment to one location, the cost of maintenance of such a combined system will be dramatically reduced.

Summary of the invention The present invention provides a system for removing selectively the product sample from the output of each desired material treatment plant, with this plant perhaps being remotely located relative to a centralized product sample analysis facility. A control computer is connected to determine the sequential operation of each product sample transfer movement determining apparatus and to coordinate the operation of the product sample analysis equipment.

The present invention provides an improved product States Patent 9 ice sample removing and transfer system which is operative to permit better instrumentation of particularly large mineral benefication plants at a substantially reduced cost and to enable a substantial improvement in the operation of those plants.

Brief descriptiong of the drawing In the drawing there is diagrammatically shown one suitable embodiment of the present invention.

There is shown in the drawing a ball mill 10 which may be a component of a large mineral benefication plant and is operative to process water and ore to provide an output slurry from the ore as feed stock for a subsequent flotation stage of the overall process. The output conduit 12 from the ball mill is tapped to remove a product sample when a valve 14, which could be a well known reciprocating type of sample device, is opened and to supply this product sample to a sampling tank 16. It should be understood that each of the involved plurality of mill equipments will be provided with such a sampling tank 16. With a product sample being cut from the production stream of its associated mill and deposited in the tank by means of a well known reciprocating type sampler with the operation of the involved valve 14 being controlled by a central computer 18 which includes programmed instructions to correlate and sequence as desired the operation of the entire facility.

The sample tank 16 is provided with a small slurry pump 20 which will normally be recirculating the sample so as to hold it in suspension. The discharge from the pump 20 Will be provided with a pinch valve 22 operated by the computer 18 in the recycle conduit 24. Additionally a diiierential pressure control pinch valve 26 is provided in the discharge conduit 28 leading to a common ring type main 30. The ring main 30 can be a small bore pipe in the order of 2 inches in diameter and can be made from polyethylene material if desired. It runs along the periphery of the mill equipment to a common analytical facility 32 located in the center of the mill facility. The maximum length path from the furthest groups of equipment will thus be approximately the same for each involved equipment and the transfer time for a product sample from any given mill to move from the furthest mill group to the common analyzing system 32 will be minimized and substantially the same. The two halves of the ring main 30 will join at a common location 33 which is connected to a source of high pressure mill water 34. There is provided a junction 36, ahead of a flow meter 38 and density meter 40, through which the product sample is caused to move when a control valve 42 is opened by the compute 18. Another control valve 44 is provided as controlled by the computer 18 and may comprise a solid state pneumatic hydraulic valve which will allow the product sample and the transfer water or simliar fluid flowing through the main 30 to be diverted either into the common analytical apparatus 32 or to a conduit 46 leading to a container 48 which supplies a subsequent thickener device.

It will be assumed that the sampling tank 16 for the one mill group 10 is full with the product sample, the pump discharge valve 22 as controlled by the computer 18 is open and the makeup water valve 50 connected to the pipe pressure mill water supply 34 and as controlled by the computer 18 is closed. On a command signal from the computer 18 the discharge valve 22 will be closed and this will cause the differential pressure control valve 26 to open, when the output pressure from the pump 20 adequately builds up, to allow the slurry product sample held within the tank 16 to be pumped into the common main 30. The computer 18 at this time controls the valve 44 to divert the transfer liquid within 3 the main 30 to the conduit 46 leading to the thickener. The slurry product sample as it enters the main 30 through the valve 26 will displace its own volume of transfer fluid such as water at reasonably high velocity through the control valve 44, which can be a solid state pneumatic hydraulic valve, leading to the thickener.

As soon as the product sample level within the sampling tanks 16 reaches a low level, at which a low level switch 52 provides an output signal to the computer 18, the valve 50 will be opened by the computer 18 to permit water to enter the holding tank 16 for several seconds after which the valve 50 is again closed by the computer 18. As soon as the slurry level within the sampling tanks 16 has once more fallen below the position of the low level switch 52 the computer will instruct the pump discharge valve 22 to open, which will cause the differential pressure control valve 26 to close and a new product sample can then be cut from the output of the ball mill by a controlled opening of the valve 14.

The high pressure mill water from the source 34 will be turned on to the system by the computer 18 opening the valve 42 so that the slug of slurry product sample with a small amount of transfer water behind it will now be pushed at high velocity by the high pressure water from the source 34 through the main 30. As soon as the density sensing transmitter device 40 notes that a high density slurry product sample is present within it, the valve 44 will be operated by the computer 18 and the slurry product sample will be diverted into the analytical tank 54. This will continue until the density of the material within the main 30 fails to a predetermined figure when the valve 44 will again be operated by the computer 18 to divert the transfer water flow back to the conduit 46 leading to the thickener and the high pressure water source 34 will be removed after a predetermined time period from the main 30 by closing the valve 42 by the computer 18.

By assuming that the product sample never stops moving once it enters the main 30 and permitting the main 30 to be purged between batch transfers of the product sample, the product sample received in the analytical tank 54 will be truly representative of the product sample cut from the conduit 12 leaving the ball mill 10. Should there be some relative motion between the solid particles and the carrier liquid this will occur uniformly throughout the length of the product sample slug and by accepting only the center portion of the Slug a greater guarantee may be provided of its being representative with reference to the original sample cut from the product output conduit 12. A refinement would therefore be to pass into the tank 54 only the center part of the sample slug while leaving the ends of the product sample slug to be passed by the valve 44 through the conduit 46 leading to the thickener. For example if the product sample slug is some 40 feet in length in a main 30 which is two inches in diameter, the chances of the middle feet of the prod uct sample slug being contaminated are very small. By insuring that the transfer water carried by the main 30 is always traveling at a high velocity, undesired salting or contamination of one product sample by deposits from another product sample will also be eliminated since the involved system will be inherently self-purging.

The analytical apparatus 32 will consist of the tank 54 operative with the pump 56 and a classifier cyclone 58 which may be used for particle size distribution analysis as described in greater detail in the referenced copend ing patent application. A flow meter 60 and a density transmitter 62 will be provided on the infeed side of the cyclone classifier 58 as well as a flow meter 64 and density transmitter 66 being provided on the overflow from the cyclone classifier 58. In addition an X-ray analysis instrument 68 is provided on the infeed side of the cyclone classifier 58 as is an X-ray analysis instrument 70 provided in the overflow conduit leading from the cyclone classifier 58 and passing the overflow slurry back to the holding tank 54. This common and centrally located analytical apparatus 32 will therefore allow both particle size determination and X-ray analysis of the selected slurry product samples to be performed on selected product samples taken from any predetermined mill group within the entire minerals benefication plant. It will be seen that the more expensive equipment is thereby concentrated at one location and may be considered as a central on-stream analytical laboratory. Thusly the expense and vulnerable equipment are limited to one area and the cost and maintenance of such a system is substantially reduced.

It should be understood that the valves controlled by the computer 18 include a servo motor circuit responsive to a control signal from the computer 18 and operative to position the valve in accordance with the output control signal from the computer. They are usually ON-OFF operative valves except for the flow and density control valves.

The present invention has been described with a certam degree of particularity. However, it should be understood that various modifications and changes can be made in the arrangement and operations of the individual parts without departing from the scope and spirit of the present invention.

I claim as my invention:

1. In product sample apparatus operative to remove a predetermined product sample from a first location of a treatment paint and to transfer this product sample to a second location of said plant, the combination of product sample removing means operative to remove a product sample at said first location of said treatment plant and including a container for said product sample, product sample transfer means operative to transfer said product sample from said container to said second location and including bypass means to divert away from said second location any material carried by said transfer means other than said product sample, product sample passage sensing means operative with said transfer means to provide a control signal in response to the presence of said product sample bemg sensed by said product sample sensing means,

and operation control means operative with said transfer means to effect the transfer of said product sample from said container and being responsive to said control signal to supply said product sample to said second location.

2. The product sample apparatus of claim 1 with said second location comprising a separate product sample analysis equipment, said combination including said product sample removing means operative to remove a liquid product sample in the form of a slurry,

and said product sample transfer means comprising a conduit cooperative with a source of transfer fluid and operative such that said transfer fluid moves said product sample from said container to said analysis equipment and with said bypass means being operative to divert away from said analysis equipment any of said transfer fluid other than said product sample.

3. The product sample apparatus of claim 1 including said operation control means being operative to control the removal of said product sample into said container and then being operative to control the transfer of said product sample to said second location while bypassing away from said second location any material other than said product sample. 4. In product sample apparatus operative with a plurality of product devices to remove a predetermined product sample from the output of a selected product device and to transfer this product sample to a common product sample analysis equipment, the combination of product sample removing means operative with each of said product devices to remove a product sample from the latter product device and including a product sample container for each said product device,

common product sample transfer means operative with each of said containers to transfer selectively said product sample from each said container to said common analysis equipment and including bypass means to divert away from said analysis equipment any material carried by said transfer means other than a selected product sample,

product sample passage sensing means operative with said transfer means to provide a control signal in response to the presence of a selected product sample at the location of said bypass means,

an operation control means operative with said trans fer means to select a particular product sample from its associated container and to control the passage of that particular product sample in response to said control signal to supply said product sample to said analysis equipment.

5 References Cited UNITED STATES PATENTS 2,380,271 7/1945 Sullivan et al. 73421 2,529,397 11/1950 Kottkamp et al. 73422 10 2,742,788 4/1956 Henton 73422 3,377,867 4/ 1968 Nitescu 73422 LOUIS R. PRINCE, Primary Examiner HARRY C. POST III, Assistant Examiner 15 US. or X.R. 

